The SARS-CoV-2 viral load in wastewater is being tested at selected wastewater treatment plants (WWTP) in Germany as part of AMELAG (“Abwassermonitoring für die epidemiologische Lagebewertung”, German for wastewater monitoring for epidemiological situation assessment). Data from 168 WWTP are currently included in the analyses. For the calendar week 40 data from 84 WWTP were available. Data from other WWTP are provided continuously.
The COVID-19 situation is assessed comprehensively in the weekly report on acute respiratory diseases (ARE weekly report) together with other indicators. A comparison between the aggregated SARS-CoV-2 viral load in wastewater and the COVID-19 incidence is shown in the weekly Grippeweb report.
The course of the viral loads aggregated across all sites is shown in Figure 1 in order to obtain an overall picture of the mean viral load and its development in Germany. To this end, weekly mean values of the viral loads (given in gene copies/liter), previously transformed by the common logarithm, are computed, first for each site and then across all sites for the respective week. The mean values are weighted according to the number of inhabitants connected to the respective site. The estimation of the regression curve is also weighted, so that weekly mean values with higher uncertainty are given a lower weight in the estimation and vice versa. A steep increase in the aggregated SARS-CoV-2 viral load can be observed for the last two weeks. The development observed over the last few weeks may still change due to late notifications, especially from WWTP with large population coverage.
Figure 1: Aggregated SARS-CoV-2 load in wastewater over time
(grey dots) along with regression curve (black line, estimated using the
LOESS method) and associated 95% confidence intervals (light blue area).
The data was last updated on Tuesday the 08.10.2024, 10 am. The latest
data used in the calculations is from the previous Wednesday’s sampling
(02.10.2024, CW 40). Shown are 7-day averages, which refer to the period
from Thursday to Wednesday; the most recent value is calculated from the
data from 26.09.2024 (CW 39), to 02.10.2024 (CW 40). The date of the
sample corresponds to the start date of the 24-hour composite sample.
The time
period displayed can be adjusted using the buttons on the top left. The
button on the right allows you to display the data points, regression
curve and confidence intervals on the logarithmic scale or transformed
back to the original scale. It should be taken into account when
interpreting the data that changes in viral loads in the low value range
are emphasized more strongly than values in the high value range on a
logarithmic scale. By hovering over the individual points the calendar
week, the date of the corresponding Wednesday, the viral load, the
number of sites and the proportion of the total population that is
included in the calculation at that time are shown.
Only data from
sites for which data is available from the last five calendar weeks is
included. The number of sites included at each point in time may differ
between the figures, as the sites with fewer
than 10 data points are not included in all figures.
Data for
further sites will be supplied subsequently.
Additionally, the course of the viral load in wastewater is shown for the individual WWTPs in Figure 2.